IP addresses are the “phone numbers” for computers connected to networks. There are private IP addresses — which are like internal phone extensions — and external or public IP addresses, which are like regular phone numbers. This is a list of local IP ranges and particular addresses of interest. The Davis Wiki logs and publicly displays the IP addresses of all users. This helps track vandalism and fake accounts. If you wish to remain anonymous, you should not use your RealName and log in from a public internet terminal (see the Privacy section below for more information.)

A full, in-depth technical explanation of IP Addresses can be found at Wikipedia.

168.150.253.1 http://wheel.dcn.davis.ca.us/ Main DCN server. Does http, smtp, pop, ftp, and shell(ssh and telnet). It is also the secondary DNS server. The ssh service is sort of old, OpenSSH_2.9p2, and doesn't accept public key authentication or sftp. Applications available include screen, lynx, ircII, tin, and gcc.

168.150.253.55 http://asoka.omsoft.com/ One of Omsoft's squid proxies. Most http access from dcn/omsoft users to web servers on the other side of this appears to be coming from here. Shell users on wheel are excepted.

10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16 - These are internal IP addresses and aren't visible on the internet. They usually mean you are behind a firewall or router. See RFC1918.

127.0.0.0/8 = your layer 3 loopback network. Whatever computer you're on, you can contact yourself at any IP in this range. Honest. Wikipedia article. Of course, some OSs are lame and don't implement this correctly and only 127.0.0.1 works as a loopback.

Most WiFi hotspots are on SBC DSL lines, the T-Mobile hotspots are the only ones in Davis with static IPs. — Then what are they?

Using the List

TODO: How to compare the above to Recent Changes

IM software generally does not allow you to see people's IP addresses, however establishing a direct connection to another IM user (to send an image or voice chat) may allow you to see their IP. You can do this by running 'netstat' from a command prompt before and after establishing the direct connection, then manually comparing the output. (this works on any OS that has a command line interface)

Some people just like making lists as a curiosity, similar to spotting trains.

Privacy

Contrary to public belief, publicly posting your IP address carries no more security vulnerability than having your phone number listed in a telephone directory. (In today's security-paranoid world, the phone book could never be created. And with the increasing popularity of mobile phones and VOIP, the phone book as we know it is on its way out.) IP addresses have been the subject of debate on the wiki because their public display could theoretically afford any malicious script kiddies that use the Wiki the opportunity to attack your computer. On the other hand, they provide yet another interesting bit of Davis trivia.

It's generally impossible to determine the location of a given user with any degree of certainty or granularity. For example, someone who lives in Davis may have home DSL on a 'dynamic IP' plan with Sonic.net, which means that they may get an IP address this week that was used by someone in Eureka last week, and will be used by someone in Los Angeles next week. Services from the big megacorps (e.g. ATT, Comcast) give more geographically accurate info in reverse DNS, but even then it's not very close to home - e.g. someone in Davis may show up as being in Sacramento, except when they show up as being in Los Angeles (as they sometimes do.)

Also, many ISPs outsource critical components of their dialup modem service to a company based in San Jose, and due to the way their network is set up anyone using such a dialup service anywhere in the state may appear to be in San Jose.

Comments:

[Some time in 2007-01] Using HostIP.info, my current IP address shows as close to home (Oakland) as one can reasonably expect - it says that I'm in San Francisco. That's not true, of course, but it's closer than, say, San Jose or Los Angeles. My mother sent me an email this morning from Eureka, California, so I looked up her IP address on the same hostip.info service - it says that IP address is in Avondale Estates, Georgia. Earlier this afternoon, a friend posted an update to a wiki that logs which IP address each contributor was using at the time. I know this person was in Davis, California when he posted his update and that he wasn't using any VPNs or proxies, and yet his IP address shows up as being in Springfield, Ohio.

This isn't even considering the folks who use such tools as a VPN or proxy server. When I was in China, I used a VPN connection back to the USA, with the end-result that my web browsing appeared to originate from Santa Rosa, California even though I was in Jiangjiajie, Hunan Province. —Graham Freeman

[2007-02-27 19:00:51] ARIN WHOIS is not always the more reliable, it plots SteveO.'s Ip to Sacramento C.C., and occasionally mine to Texas. Just noting, ~DavePoole

2007-02-28 20:45:43 Dave, (1) there's no other RIR besides ARIN that would serve IP blocks in North America, and (2) it's a matter of how things are deployed, not of reliability. e.g. the IP address 208.67.222.222 shows up as being in San Francisco, even though equipment that answers on that IP is also deployed in Palo Alto, Washington DC, Seattle, New York City, and London. —GrahamFreeman

I asked Omsoft about it a few years ago and they said they had no plans. Hurricane Electric says they will give you a T1 or something, but I can't afford that of course. Currently I use Freenet6 for a tunnelbroker because they give me a /48 and allow irc. I have also used Hurricane Electric because they are much better connected to this area, being in the Bay Area, but they only give a /64 and don't allow irc. Have you used any others? What are your experiences? —NickSchmalenberger

I actually do use HE and have been fairly happy with them as a v6 provider. I asked Omsoft about it a while back too, and at the time they had less plans ;-). It'd be nice to get something real rather than the /64 that HE gives me. Which is fine, really, for me but it's harder if you don't bridge your internal wireless and wired networks (I do). I didn't actually know about the irc restriction (though that explains why I never am connected to IRC via ipv6 when I thought some of the servers supported it) — WesHardaker